Inflatable boat



Feb. 17,1959 0, MARZ 2,873,459

INFLATABLE BOAT Filed Jan. 17, 1956 5 Sheets-Sheet l jm emoni 4 222 flfr Feb 17, 1959 I o, MARZ 2,873,459

INFLATABLE BOAT Filed Jan. 17, 1956 5 Sheets-Sheet 2 jm/emon' Feb. 17, 1959 o. MARZ 2,873,459

INFLATABLE BOAT Filed Jan. 17, 1956 5 Sheets-Sheet 3 o. MARz INFLATABLE BOAT Feb. 17, 1959 5 Sheets-Sheet 4 Filed Jan. 17, 1956 Inventor? 4Z'/% Feb. 17, 1959 o, MARZ 2,873,459

INFLATABLE BOAT Filed Jan. 17, 1956 5 Sheets-Sheet 5 .Zhrenton United States Patent 2,873,459 Patented Feb. 17, 1959 INFLATABLE BOAT Otto Miirz, Munich, Germany, assignor to Metzeler Gummiwerke A. G., Munich, Germany Application January 17, 1956, Serial No. 559,721 "Claims priority, application Germany January 21, 1955 3 Claims. (Cl. 9 2) This invention relates to an inflatable boat or dinghy of the type having several longitudinally extending hoseshaped cells of caoutchouc or a caoutchouc substitute or fabrics coated and/ or impregnated therewith.

Hitherto, boats of this kind, constructed in the form of a cayak, or a canoe, or the like, consist of an upper and lower skin each made of two parts forming the two side walls of the boat and being united with each other under formation of a corresponding through keel extending from the bow to the stern. In order to give to these boats of a V-shaped cross section at least a certain bottom-like extension and thus to create a passable seating accommodation and to reduce the danger of capsizing, corresponding transverse frame members or bottom grates of wood or the like as well as backrest and spreading means must be inserted in such boats. However, such means are rather bulky and heavy.

It is an object of the present invention to provide an inflatable boat which in a deflated condition can be folded together or rolled up to a compact unit of a relatively low weight.

Another object of the invention is to provide an inflatable boat permitting easy boarding and comfortable sitting and having a good and safe trim.

With these and further objects in view, according to the present invention the inner and outer skins of the boat, forming together the board sides and the bottom thereof, and the deck wall imparting to the inflated boat its shape and stability and being in a unitary connection with the board sides, e. g. by agglutination or vulcanizing, consist each from board to board of a single integral piece of material, the inner and outer skins being united in such a way that rollor hose-shaped cells are obtained by the provision of spacers, in such a way that each of the rolls forming the bottom of the boat has an equal relatively small diameter and that the lateral rolls forming the board sides of the boat have a relatively larger diameter which is increasing from roll to roll in an upward direction, each lateral roll being shorter than the adjacent lower lateral roll or at least the uppermost lateral rolls passing over into the deckline of the boat with corresponding taper or diminution.

With such a construction all additional bulky and weighty stiffening members can be dispensed with and yet an easy boarding and comfortable seating accommodation is provided and a good, and safe trim is ensured.

According to a special feature of the invention the covering or deck has a manhole for boarding and disembarking and comprises also inner and outer skins each consisting of a single cut of material united with each other in such a way that longitudinal and/ or transversely extending roll-shaped cells are obtained by the insertion of spacers. Preferably the spacers are arranged in such a way that several roll-shaped cells extending in the longitudinal direction of the boat are arranged side by side in the rear part of the deck, while a central rollshaped cell extending in the longitudinal direction of the boat is arranged in the forward part of the deck and a 2 plurality of roll-shaped cells are arranged side by side on both sides of the central roll, transversely to the longitudinal direction of the boat.

According to a still further feature of the invention a keel of triangular cross section consisting of solid rubber is connected to the boat with its base, preferably only below the waterline of the hull, by agglutinating or vulcanizing, for ensuring a straight guiding of the boat in the water. Inserted between the hull of the boat and its keel is a strip of fabric which is equivalent to the fabric of the boat and fixedly connected on the one side to the boat hull and on the other hand to the keel.

A special advantage is attainable by providing the keel, transversely to its length, near the middle or additionally on several points preferably succeeding each other from the middle, at any intervals, with incisions Or recesses projecting nearly to its base and permitting a folding together of the boat and of the keel.

Other and further objects, features and. advantages of. the invention will be pointed out hereinafter and appear in the appended claims forming part of the application.

In the accompanying drawings several now preferred embodiments of the invention are shown by way of illustration and not by way of limitation.

Fig. 1 is a perspective view, from the rearward top side, of an inflatable boat having the invention applied thereto,

Fig. 2 is a plan view thereof,

Fig. 3 is a cross section on line 33 of Fig. 2,

Fig. 4 is a cross section on line 4-4 of Fig. 2,

Fig. 5 is a cross section on line 5-5 of Fig. 2,

Fig. 6 is a plan view on the inner surface of one-half of the outer skin of the inflatable boat which is spread in a plane surface and still in the state of assembling, with a part of the spacers for the formation of cells already attached,

Fig. 7 is a fragmentary cross-sectional view, on a larger scale, according to the lines 33 or 4-4 or 5-5 of Figs. 3-5,

Fig. 8 is a perspective view from the rear top side, of the inflatable boat with the means for inflating it,

Fig. 9 is a fragmentary cross-sectional view on a larger scale, through a part of the boat where an inflating device as per Fig. 8 is arranged,

Fig. 10 is a sectional view showing an intermediate state in the preparation of the spacer strip,

Fig. 11 is a sectional fragmentary view illustrating the fitting of the spacer strip, and

Fig. 12 is a similar view showing an initial stage in the inflating.

Similar reference numerals denote similar parts inthe different views.

Referring now to the drawings in greater detail, it will be seen that the inflatable boat consists substantially of an inner skin 1, and an outer skin 2, Figures 3 to 5, 6, '7 and 9. Each of the outer and inner skins 1, 2 of the boat extends from the board 3 to the board 4 and consists of a single, plane and integral cut of material. Both cuts of material are kept separate from each other within the range of the boards 3, 4, except for the borders or lobes, by spacers 32, Figs. 6, 7, 9, l2, forming intercommunicating air cells such as those shown at 5 to 20. Each of the roll-shaped cells ill-15, Fig. 3, forming the bottom is of the same relatively small diameter. The roll-shaped cells 95 or 16Zti, Fig. 3, on the contrary, succeeding the roll-shaped cells 10 and 15 and forming the side walls of the hull, have a diameter which is increasing from one roll to the next up to the respective board, each lateral roll, for instance 18, 19, 20, Fig. 1, being shorter than the roll adjacent thereto on the lower side; or at least the uppermost side rolls are shaped in such a way, with a corresponding taper 3 of their ends, that they pass into the upper deckline of the boat.

Each of the spacers 32, Figs. 6, 7, 9-12, preferably consists of two strips 51, 52 of a relatively thin and flexible fabric which is gummed on one side. The two strips are superposed with their gurnmed faces, in such a way that about two-thirds of the middle part are actually joined with each other, to form the web 50 of the spacer strip. The remaining lugs or flanges left on both lateral edges and occupying each about one-sixth of the total width are bent over and afterwards joined with the inner surfaces of the outer and inner skins, by rolling, as will be hereinafter described.

The lugs 53, 54 of one of the two strips, for instance of strip 52, are inwardly bent by 180 in such a way that their gummed sides face outwards, Fig. 10, so that their non-gummed surfaces engage the web 50. Now the strip prepared in this manner is folded about a central longitudinal line 55, Figs. 10, 11, in the direction indicated by the arrows 6t) and 61, in such a way that the two halves of the non-gummed surface of the strip 51 engage each other. The lugs or flanges 56, 57 of the strip 51 which are not bent over project beyond the web 50 folded together in this manner, in such a way that their gummed surfaces are approximately in a common plane with, or in the same direction as, those of the lugs 53, 54. The spacers prepared in this manner are advantageously wound up on a drum from which they arethen cut off in the required length and attached to the inner surface of one of the two skins of the boat, for instance to the outer skin 2, Fig. 6, in the required position, in a straight line, i. e. in such a way that the center line of the central spacer strip 32 arranged symmetrically over the keel 30 in Fig. 7, extends between the two end points of the skin 2. The further spacer strips 32 are then attached parallel to the said central spacer 32 at a distance from each other which corresponds to the intended size for instance, of the cells 12, 13, Fig. 7. When all of the spacer strips 32 prepared in this manner have been attached to one of the skins of the boat, for instance to the inner surface of the outer skin 2, the other skin,

for instance the inner skin 1, is put thereon in such a way that the outer contours of the two skins coincide with each other and that the inner surface of the respective skin engages the gummed sides of the flanges 53, 56, Fig. 11. The flanges 54, 57 and 53, 56 are-now tightly pressed on the respective inner surfaces of the two skins 1, 2. This may be effected for instance by a tool provided with a rotatable roller which is rolled over the skin 1 in the region of the flanges 53, 54 or 56, 57 with a certain pressure. It will be understood that for the sake of clarity, the strips in Figs. 10, 12 have been indicated by solid lines although they actually have a certain thickness.

Referring to Fig. 6 it will be seen that the spacers 32 terminate already a certain distance before the adjacent borders of the inner and outer skin 1, 2. If the inner and outer skins are then united at their edges into tightly superposed borders or lobes during the assemblying, an open channel connecting the interior of the adjacent rolls, for instance 12, 13, will remain between each of the inner boundaries of this lobe and the adjacent ends of the spacers 32. Owing to the channels thus provided (and additional perforations 32a which may be provided in the spacers, if desired), the air volumes within the rolls 220 communicate with each other, said rolls, especially in an inflated state, causing and maintaining the tendency in the combination of inner skin 1, outer skin 2 and spacers 32, curved in the form of a boat bull, to stretch into a plane or straight position.

The tension thus existing especially in the walls of the hull is counteracted by a deck or covering which forms a manhole 20a and consists preferably of a rear part 21a and a front part 21b, Whose outwardly directed edges are connected with the above mentioned borders or lobes of the inner and outer skins 1, 2, which are drawn upwards in the form of a 'boat hull, forming a structural unit therewith, for instance by agglutination or vulcanization. The covering 21a, 21b thus united with the hull of the boat consist each of an integral upper (2161', 21b) and lower (21a, 21b) piece of material, these cuts of material also being united so as to form roll-shaped cells extending in a longitudinal and/or transverse direction and obtained by the insertion of spacers 32, substantially in the manner as hereinbefore described with reference to the cuts 1 and 2.

Preferably several roll-shaped cells 22-26 extending in the longitudinal direction of the boat are provided in the rear part of the covering 2111, while a central roll-shaped cell 27 extending in the longitudinal direction of the boat and several roll-shaped cells 28 extending transversely thereto on both sides of the central roll, are provided in the front part 21a of the covering. By this construction and subdivision of the main parts 21a and 21b of the covering which give to the hull its Shape and stiffness, more particularly in an inflated position, it is additionally ensured that the respective part of the boat is drawn upwards, whereby its stability is additionally increased.

Owing to the communication established by the air channels between all of the cells provided in the bottom and side walls of the hull or in the coverings 21a and 21b thereof, respectively, in the embodiment as illustrated only three connections 33, 33a, 33b, Figs. 8, 9, are provided for blowing up the boat, said connections consisting according to the exemplification shown in Fig. 9 of a length of hose 33, a flange 34 fastened to one end of this hose, by vulcanization, and a covering member 35. The length of hose 33 extends through an opening of the covering member 35 and is connected to the roll-shaped cell, for instance, cell 6, into the interior of which the length of hose 33 issues, by per se known means, for instance by agglutinating or vulcanizing. The outwardly directed end of the length of hose is closed in per se known manner, by a plug 36 formed with a flange 36'.-

The inflatable boat consists of the hull, Fig. 1, the coverings 21a, 2111 giving to the hull its shape and stability and preferably also being inflatable, and a keel secured to its lower central longitudinal part, Figs. 1 and 8, and made of a solid piece of semi-hard or hard rubber. Halfway between its ends the keel 30 is provided with an incision or recess 3% of such a depth that the keel 30 permits the folding of the deflated boat. Where it is intended to fold the boat several times, the keel 30 may be formed with further recesses 30b, 300, etc., spaced from each other by a distance corresponding to the intended final size of the pack constituting the folded boat. Each of said recesses 30a, 30b, 300 may extend to a depth more or less nearly to the base of the keel 30 which preferably may be produced by injection-molding. The keel is advantageously secured to the outer skin of the hull by insertion of a strip of material 31 consisting of the same material as the rest of the boat, for instance the inner and outer skins 1, 2, and the spacers 32. The keel 30 may be connected to the strip of material 31 and the latter in its turn may be connected to the outer surface of the outer skin 2 of the boat by agglutination or vulcanization.

Preferably, the base of the keel extends approximately up to the middle of the air cells 12, 13 of the boat disposed above the keel and defined by spacers 32, its center line preferably coinciding with that of the central longitudinally extending spacer.

The boat may or may not be vulcanized. Preferably, the various parts of the boat shown in Figs. 1 to 9 are assembled entirely or partly into the hull of the boat in a non-vulcanized condition, by agglutinating, and the complete hull is then vulcanized. It is also possible, however, to assemble individual non-vulcanized parts which are then separately vulcanized. Furthermore, it is also .5 possible, by way of alternative, to use readily vulcanized parts which are then connected with each other by suitable per se known adhesives, for instance on the basis of caoutchouc.

It will be understood that as the boat after the assembling and vulcanization is inflated, the inner and outer skins 1, 2 of the boat hull or those of the coverings 21a, 2112, respectively, are lifted oflf from each other as the inflating proceeds, so that the web 50 of the spacer 32 is stretched from its folded position, Fig. 11, into its final position, Fig. 7, through the intermediate position indicated in Fig. 12.

While the invention has been described in detail with respect to a now preferred example and embodiment of the invention it will be understood by those skilled in the art after understanding the invention that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefore, to cover all such changes and modifications in the appended claims.

I claim:

1. An inflatable boat comprising a hull including an inner skin and an outer skin forming together the side and bottom walls of the hull, each of said skins consisting of a single integral piece of water-tight flexible material, means connecting said skins along lines extending generally longitudinally of the boat, said connecting means comprising flexible elongated members of I-shaped cross-section having the outer faces of the flanges secured to the inside faces of the skins, means securing said skins along their longitudinal edges to form a water-tight structure having a series of tubular air cells therein, means connecting the front and rear edges of the skins to form the bow and stern of the boat, said hull normally having a tendency to lie flat when deflated, and a closure comprising a third piece of a water-tight flexible material permanently structurally connected with and extending from one longitudinal edge of the skins to the other, said closure being narrower than said skins so as to hold the skins in concave form when inflated, said closure having an opening therein for access to the interior of the boat.

2. In a device as claimed in claim 1, said closure comprising two skins connected to one another along spaced lines.

3. In a device as claimed in claim 2, the lines of connection between the two skins of the closure extending transversely of the boat in front of the opening and longitudinally of the boat to the rear of the opening.

References Cited in the file of this patent UNITED STATES PATENTS 1,981,871 Manson Nov. 27, 1934 2,739,321 La Colette Mar. 27, 1956 FOREIGN PATENTS 19,769 Great Britain 1898 326,248 Italy May 7, 1935 

